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| author | Stefan Hajnoczi <stefanha@redhat.com> | 2017-05-10 10:19:18 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-05-18 16:59:06 +0200 |
| commit | f4660cc994e12bae60d6f49895636fba662ce0a1 (patch) | |
| tree | 1b2772f70601a954a790e19f75333dc993163ecd | |
| parent | ff35eb23de9be50fbe3405f35244b5e82eadc5fa (diff) | |
| download | linux-f4660cc994e12bae60d6f49895636fba662ce0a1.tar.gz linux-f4660cc994e12bae60d6f49895636fba662ce0a1.tar.bz2 linux-f4660cc994e12bae60d6f49895636fba662ce0a1.zip | |
vhost/vsock: use static minor number
Vhost-vsock is a software device so there is no probe call that causes
the driver to register its misc char device node. This creates a
chicken and egg problem: userspace applications must open
/dev/vhost-vsock to use the driver but the file doesn't exist until the
kernel module has been loaded.
Use the devname modalias mechanism so that /dev/vhost-vsock is created
at boot. The vhost_vsock kernel module is automatically loaded when the
first application opens /dev/host-vsock.
Note that the "reserved for local use" range in
Documentation/admin-guide/devices.txt is incorrect. The userio driver
already occupies part of that range. I've updated the documentation
accordingly.
Cc: device@lanana.org
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | Documentation/admin-guide/devices.txt | 4 | ||||
| -rw-r--r-- | drivers/vhost/vsock.c | 4 | ||||
| -rw-r--r-- | include/linux/miscdevice.h | 1 |
3 files changed, 7 insertions, 2 deletions
diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt index c9cea2e39c21..6b71852dadc2 100644 --- a/Documentation/admin-guide/devices.txt +++ b/Documentation/admin-guide/devices.txt @@ -369,8 +369,10 @@ 237 = /dev/loop-control Loopback control device 238 = /dev/vhost-net Host kernel accelerator for virtio net 239 = /dev/uhid User-space I/O driver support for HID subsystem + 240 = /dev/userio Serio driver testing device + 241 = /dev/vhost-vsock Host kernel driver for virtio vsock - 240-254 Reserved for local use + 242-254 Reserved for local use 255 Reserved for MISC_DYNAMIC_MINOR 11 char Raw keyboard device (Linux/SPARC only) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 3acef3c5d8ed..3f63e03de8e8 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -706,7 +706,7 @@ static const struct file_operations vhost_vsock_fops = { }; static struct miscdevice vhost_vsock_misc = { - .minor = MISC_DYNAMIC_MINOR, + .minor = VHOST_VSOCK_MINOR, .name = "vhost-vsock", .fops = &vhost_vsock_fops, }; @@ -778,3 +778,5 @@ module_exit(vhost_vsock_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Asias He"); MODULE_DESCRIPTION("vhost transport for vsock "); +MODULE_ALIAS_MISCDEV(VHOST_VSOCK_MINOR); +MODULE_ALIAS("devname:vhost-vsock"); diff --git a/include/linux/miscdevice.h b/include/linux/miscdevice.h index 762b5fec3383..58751eae5f77 100644 --- a/include/linux/miscdevice.h +++ b/include/linux/miscdevice.h @@ -54,6 +54,7 @@ #define VHOST_NET_MINOR 238 #define UHID_MINOR 239 #define USERIO_MINOR 240 +#define VHOST_VSOCK_MINOR 241 #define MISC_DYNAMIC_MINOR 255 struct device; |